Near-infrared Yablonovite-like photonic crystals by focused-ion-beam etching of macroporous silicon

We report on the fabrication of three-dimensional (3D) Yablonovite-like pho tonic crystals by focused-ion-beam (FIB) etching of macroporous silicon. Cr ystals containing up to 25x25x5 lattice cells are fabricated with a submicr onic period of similar to0.75 mum. Photonic band gaps at wavelengths close to 3 mum are demonstrated from reflection measurements and confirmed by num erical calculations. The combination of plasma or chemical etching with FIB micromachining appears to be promising for the fabrication of a large vari ety of multiple-period 3D photonic crystals at optical wavelengths. (C) 200 0 American Institute of Physics. [S0003-6951(00)00245-X].